I suggest you refer to the following methods
1. Hear your own echo during call. This phenomenon may be the reason for the other party's equipment. It is recommended that the other party switch the call method (listen to simple cuts or lift or listen to simplicity);
2. When the other party hears echoes, please pay attention to check whether the microphone is blocked. For example, the finger cover may cause the echo, you can try it by adjusting the handheld holder;
3. Causes of network reasons, it is recommended that you contact the operator to open the Volte high -definition call business of the phone card to try. The signal bar shows the VOLTE icon, which means that the hand equipment book to the VOLTE network, the call quality is better;